Israel landed commandos on the outskirts of Damascus overnight, state media said on Thursday, in one of its biggest military operations so far against Syria's new government.
The attack is believed to have hit a military site once used by Iranian intelligence under the rule of Syria's former president Bashar Al Assad, who was overthrown at the end of last year. A source said Israeli troops went in to retrieve surveillance equipment.
The Israeli operation appeared to be the largest of several strikes on Syria this week, which have been condemned by Arab countries. At least nine Syrian soldiers are believed to have been killed.
A source in Jordan said Israel heavily bombed a Syrian base in the Jabal Mani area, before sending in troops to retrieve surveillance and eavesdropping equipment planted underground, killing at least three Syrian soldiers.
The authorities in Damascus said another six soldiers had been killed in earlier Israeli air strikes on the area in the past 48 hours.
"The explosions were huge, designed to make sure that Jabal Mani would be empty of the Syrians before the Israelis went in," the source said. The area has been a hub for fibreoptic and aerial communications for decades, with Iranian intelligence upgrading the systems during the last decade of Mr Al Assad's rule, they added.
Syrian state media said troops from Syria's army had found the "monitoring and eavesdropping devices" on Tuesday. While attempting to deal with them they were hit by Israeli strikes, followed by an "airborne landing", it said.
Tension has been high between the two countries since an Israeli military intervention prevented a Syrian government takeover of the mostly Druze province of Sweida last month.
On that occasion Israel bombed symbols of government power in Damascus, including the Defence Ministry headquarters. The unrest has since prompted Druze calls for separation, an unlikely prospect without further Israeli intervention.
The Israeli military did not comment on Wednesday's operation. Defence Minister Israel Katz said only that "our forces are operating in all combat zones day and night for the security of Israel," including Gaza and Lebanon.
Prime Minister Benjamin Netanyahu told a Druze leader in Israel on Thursday that his government's aims include "creating a demilitarised zone" and establishing a humanitarian corridor to areas caught up in
Israel has regularly struck Syria since rebels toppled Mr Al Assad but has also opened talks with the new authorities in Damascus on a security deal, in a process mediated by the US.
The Assad regime was overthrown and replaced by Hayat Tahrir Al Sham, a former splinter group from Al Qaeda. HTS sought to accommodate Israel by engaging in peace talks that have not been able to contain differences over the fate of Sweida's Druze. The minority sect is also present in Israel.
Syria's official news agency Sana said Israel landed airborne troops overnight in Jabal Mani, about 12km south of Damascus, after bombing the site in the 48 hours before. It said this led to the "martyrdom of several [troops)], the wounding of others and the destruction of machinery".
"Intensive reconnaissance flights" by Israel were also taking place in the area, the agency said. It quoted a government source as saying Syrian soldiers had found “surveillance and eavesdropping devices” at the site before it was hit by Israeli air strikes on Tuesday and Wednesday.
Syrian army units destroyed some of the systems, Sana added. The Syrian Observatory for Human Rights said the site contained weapons used by Iran-backed Hezbollah, Mr Al Assad's main non-state ally before he was ousted.
Reuters quoted a military source as saying that Syria believes some equipment was left behind, perhaps by Iran-backed militias. The new Syrian army – put together after Mr Al Assad's fall – has in recent months established a token presence in the Kiswah area, south of the Syrian capital.
On Tuesday, Syria's Foreign Ministry said Israel's "aggressive practices constitute a direct threat" to regional security. The UAE on Wednesday condemned Israel for its "dangerous escalation and violations" in Syrian territory, which were also condemned in similar terms by Saudi Arabia.
Israel has repeatedly cited security concerns in its military interventions in Syria, including what it sees as an obligation to protect the Druze minority in the south, who share links with members of the sect living in Israel.
"Israel wants sectarian strife to take hold in Syria but we want peace to prevail in the region,” Syria's Foreign Minister Asaad Al Shibani said during talks in Turkey this month.
The Druze unrest has set back Mr Al Shara's efforts to consolidate control of Syria, with a powerful Kurdish militia also proving difficult to integrate. Israel also occupies much of a UN-patrolled demilitarised zone on the Syrian-held side of an armistice line between the two countries established in 1974.
Mr Al Shibani last week met an Israeli delegation in Paris to discuss enhancing security in the region. The discussions focused on de-escalation and non-interference, as well as monitoring the ceasefire in Sweida governorate, among other issues.
